Right ventricular longitudinal strain: a tool for diagnosis and prognosis in light-chain amyloidosis

Light-chain (AL) amyloidosis can lead to an infiltrative cardiomyopathy with increased wall thickness (IWT) of very poor prognosis. Our primary aim was to analyse the right ventricle (RV) in patients with IWT to discriminate AL amyloidosis from IWT due to hypertrophic cardiomyopathy (HCM) or to arterial hypertension (HTN). Our secondary aim was to assess if RV dysfunction predicts overall mortality in cardiac AL amyloidosis.

We retrospectively and consecutively compared clinical, biological and echocardiographic data of 315 patients with IWT: 105 biopsy-proven AL amyloidosis patients, 105 patients with HCM and 105 patients with HTN. The prognostic value of these parameters was analysed in the AL amyloidosis group.

Free-wall right ventricular longitudinal strain (FWRVLS) worse than -21.2% discriminates AL amyloidosis [area under the curve (AUC) = 0.744)] from patients with IWT due to other aetiologies. In AL amyloidosis, FWRVLS is the strongest echocardiographic prognostic marker with AUC =0.722 and -16.5% as the optimal cut-off value, beyond which overall mortality increases significantly. It is also the only independent echocardiographic predictor of overall mortality (HR =1.113; 95%CI 1.029-1.204; p = .007), even when adjusted to the Mayo stage and global left ventricular longitudinal strain.

FWRVLS should be considered in the diagnostic and prognostic workup in light-chain amyloidosis.